I am nominating this for featured article because after all the comments I have received on PRs and on talk pages, I believe that it is FA-ready. It seems to be well-written, does not have any bias, and is comprehensive in its coverage. StringTheory11 (t • c) 01:07, 12 October 2012 (UTC)
Comments from indopug
I've always been interested to know this: how exactly did the atomic-mass-based Mendeleev table come to become the modern, atomic-number-based one? (in school I learnt that his table was thus quite distinct from the modern one; here, the difference is presented as a subtle, gradual one. Hence, I'm a little confused.) Was it Mendeleev himself who made this change; if not, who?
That would probably have been Henry Moseley. I'm more interested in the question: when did Mendeleev's short (8-column) periodic table (the one still used in Russia - shouldn't it be mentioned here, BTW?) get replaced by the 18-column one and when did the long-form (32-column) table gain more popularity? This page reports a surprisingly accurate 32-column periodic table from 1892; the 18-column periodic table had to wait until 1923. Even then, the 8-column one was still more popular until the 18-column one gained popularity after World War II (probably due to Seaborg). That page even has a periodic table with the "uranide" series (elements 92-106 all under tungsten). Double sharp (talk) 04:51, 12 October 2012 (UTC)
"Hence, fluorine is the most electronegative of the elements (not counting noble gases) while caesium is the least, at least of those elements for which substantial data is available." – noble gases are the most electronegative of the elements?
It's probably using the Allen scale rather than the Pauling scale, as only Kr, Xe, and Rn have known Pauling electronegativities. Under the Allen scale, neon has the highest electronegativity, with fluorine and helium as second and third place respectively. I do note, however, that the Allen scale is not mentioned. Double sharp (talk) 04:51, 12 October 2012 (UTC)
I wonder if the Bohr model and Relativistic Dirac equation subsections are excessive? The latter is ably summarised by the Feynman sentence (and the former can similarly be cast as a couple of sentences in Future and end of the periodic table)
I've removed the summary paragraph that you were talking about, so DoneStringTheory11 (t • c) 19:12, 14 October 2012 (UTC)
I suspect that most people who search for "period table" want mainly to look at the table itself. Is there a case for a to look at the table itself click here line at the top?—indopug (talk) 03:25, 12 October 2012 (UTC)
In the periodic table template, it is written that "the short form or Mendeleev-style, which omits groups 3 to 12". This sounds ambiguous. I know it's really trying to say that the transition metals are placed into the main groups, but it sounds as though the transition metals are not placed in the table. It would be better, though, if you could give a more detailed account of the Mendeleev-style table.
The French version of this article has a lot of interesting information about the history of the periodic table, such as how those historic tables looked like (although it does have a shortage of citations). Some of this material could be included into the English article. Double sharp (talk) 11:52, 12 October 2012 (UTC)
You mention in the "Groups" section the trivial names. Why not have a table on the right showing all the trivial names (I've put one to the right)? It would be quite informative. Many citations can be found on WT:ELEM (thanks Sandbh). Please note, however, that those for groups 11–14 are rare and not often used (and this should be mentioned in the article). Double sharp (talk) 11:58, 12 October 2012 (UTC)
BTW, how exactly does the ADOMAH PT help with writing electron configurations? So does the standard PT, and neither seems to allow for the exceptions to the Madelung rule. Double sharp (talk) 02:08, 19 October 2012 (UTC)
This appears to be unsourced, so I have removed it. StringTheory11 (t • c) 23:32, 19 October 2012 (UTC)
Drive by Duplicate links detector found the following overlinks in the body of the text: Julius Lothar Meyer, flerovium, livermorium, isotopes, carbon, alkali metals, lanthanum, lutetium, electron shell, quantum theory, lutetium, lanthanides, hafnium, transition metals, fluorine, germanium, lead, d-block contraction, flerovium, copernicium, atomic number, relativistic, Dirac equation Jimfbleak -talk to me? 10:39, 12 October 2012 (UTC)
The lead. There is a mismatch between the sequencing of the lead (which is fine) and that of the main body of the article. In the lead the history of the periodic table follows the definition-organization-components content whereas in the main body of the article the order is the other way round i.e. the history comes first then the discussion of components and organization etc. Also, the discussion in the lead of 'blocks' is disconnected from anything tangible i.e. it is not made clear where these blocks are located.
First systemization attempts. Should say something about the work of de Chancourtois (1862) since he published the first system of elements in 1862, via his telluric screw, showing periodicity; also Odling(1864) and Hinrichs (1867).
Mendeleev's table. The first sentence refers to Mendeleev's table (1869) and that of Meyer (1870) but the supporting citation only refers to Mendeleev's table. Meyer in fact published his table in 1864, as noted in paragraph two of the previous section. The third sentence talks about the success of Mendeleev's table but does not explain what is meant by "success".
Periodic trends. The picture duplicates content set out in the earlier Periods section. Three of the trends shown in the picture—EA, metallic character, nonmetallic character—are not elaborated in the accompanying text. I have read paragraphs 1–2 many times and still do not understand their relevance. Much duplicated content. More editing required.
About this...do you think that the section is currently excessive? In my opinion, since there is already a periodic trends article, it would make more sense to trim this section to a minimum (which would entail removing all the subsections), and simply have the main article link at the top. Does anyone else have any input on this? StringTheory11 (t • c) 04:12, 18 October 2012 (UTC)
Yes; agreed. It is currently the largest section of the article and will become even bigger with some more content about metallic/nonmetallic character. So there should be scope for some trimming. Sandbh (talk) 00:28, 20 October 2012 (UTC)
Atomic radii. Paragraph 2 says that, 'As the atomic number increases along each row of the periodic table, the additional electrons go into the same outermost shell...'. This is not the case with either the 'd' block or 'f' block elements, where extra electrons usually go into the outermost but one shell.
Paul-Antoine Giguère's periodic table. Need a better reference to a 3D periodic table here. Any periodic table which omits hydrogen and helium due to their anomalous properties is dodgy. H and He are still subject to the periodic law notwithstanding their anomalous properties.
Short periodic table. A short periodic table, as per Mendeleev, should be included in this article, together with comments that this version is still popular (understandably so, given its provenance) within the CIS, at least in Russia and Belarus.
Hmmm, could someone else do this one? I know literally nothing about the short form, due to the fact that it is almost never used in the United States. StringTheory11 (t • c) 22:34, 13 October 2012 (UTC)
Done I am pleased to say Sandbh (talk) 06:51, 3 November 2012 (UTC)\
No wait, we still need the text saying it's popular in a big region of the world. I don't know what to write there. I think that the Soviet Union didn't adopt this form of the table because it was a) wrong time (the war was just over, it wasn't time when science was invested) b) wasn't really needed, especially given that the original form was made in Russia and the new one was American, and such an important element of science couldn't be turned from own country's into "bourgeois'" (later they even launched a program to prove that almost all of science was discovered or found in Russia, including bicycles, radio, Center of Europe, and the whole humankind (even though the latter was just a hypothesis, if you ask anyone on the street here in Moscow, "Who invented the radio?", you'll hear not "Marconi," as you could expect, but "Popov" instead.) It's my OR though, I have no sources.--R8R Gtrs (talk) 18:08, 5 November 2012 (UTC)
Most common periodic table (citation), and origin. The article text needs to say that the medium form of the periodic table is the common or standard form, together with a supporting citation (there used to be one of these so not much work required). At the moment this is said only within the Periodic table (standard form) template, without a supporting citation. An explanation as to the origin and popularity of the common or standard form, per Deming (1923?), is also required. Sandbh (talk) 04:18, 13 October 2012 (UTC)
Other commentsComment: Per WP:When to cite a source is needed for: Under this approximation, any element with an atomic number of greater than 137 would require 1s electrons to be traveling faster than c, the speed of light. Hence the non-relativistic Bohr model is inaccurate when applied to such an element. in this section. JZCL 15:25, 13 October 2012 (UTC)
Why would it be necessary here? Whenever the fraction of the speed of light is greater than one, it is self-explanatory that the object would have to be moving faster than light, and thus, it would be obvious that the equation breaks down for z > 137. I don't see why a cite would be needed here. StringTheory11 (t • c) 19:22, 13 October 2012 (UTC)
Question -Is elaborating the Bohr model and Relativistic Dirac equation predictions really necessary in the "Future and end of the periodic table" section? I could hardly understand what the equations mean. I could be wrong, but it might be better to not go into details and just briefly mention what those models predict, and save the details for that main extended PT article. -- FutureTrillionaire (talk) 01:43, 18 October 2012 (UTC)
Future and end of the periodic table. Rename the section to Open questions or Open questions and controversies. Add new content about: the location of hydrogen; the composition of the scandium group; where do the transition metals end; and whether or not there is an optimal form of periodic table. Sandbh (talk) 00:28, 20 October 2012 (UTC)
Sometimes even the beginning of the transition metals is disputed, with Sc and Y taken as not being transition metals because they almost always form Sc3+ and Y3+ ions, which have empty d-orbitals. A ref. Double sharp (talk) 08:51, 20 October 2012 (UTC)
Section-headers: Per MOS:HEADINGS, section-headers should be statements rather than questions. Currently there are three consecutive subsections:
Which elements are transition metals?
Which elements make up group 3?
Is there an optimal form of periodic table?
Every subsection there is within the "Open questions and controversies" section so there's no need to reiterate that there is uncertainty about each subtopic. I adjusted them in the article but am not sure the results are optimal for each. DMacks (talk) 04:42, 27 October 2012 (UTC)
Done (good call) Sandbh (talk) 06:15, 27 October 2012 (UTC)
Quick comment I heard that a dream inspired Mendeleyev to create the table. Is this true and does it belong to this article? Regards.--Tomcat(7) 22:15, 28 October 2012 (UTC)
it's a very common belief, born while he was still alive, and he commented that he had been thinking of it for 20 years, and that it was very unfair to say it was a dream instead. Note also he didn't think the table was his best contribution to science. About that if it belongs, let's hear the author.--R8R Gtrs (talk) 22:31, 28 October 2012 (UTC)
Eh, to be honest, I somewhat question the notability of this, especially seeing that we have a history of the periodic table article. It may be suited for that article, but certainly not this article. StringTheory11 (t • c) 04:31, 29 October 2012 (UTC)
Support. It's a good read, and a great topic.
Perhaps when you mention "atomic number" in the second sentence, you should briefly explain what it is (beyond just the original link you have), since that is such a key part to the table.
"Of these elements, 114 have been officially recognized and named by the International Union of Pure and Applied Chemistry (IUPAC). A total of 98 of these occur naturally, of which 84 are primordial. The other 14 elements only occur in decay chains of primordial elements." - pardon my math, but 98+14 is 112. What about the other two? Was this not updated when Livermorium and flerovium was added this year?
You appear to be right here; livermorium and flerovium were not added. Done. StringTheory11 (t • c) 04:14, 3 November 2012 (UTC)
"No element heavier than einsteinium (element 99) has ever been observed in macroscopic quantities in its pure form." - that contradicts the lede, which says "Of these, all up to and including californium exist naturally".
Sorry, how does this contradict? Californium is element 98, while einsteinium is number 99. I don't see the contradiction here. StringTheory11 (t • c) 04:14, 3 November 2012 (UTC)
But the way it says "heavier than einsteinium" does not say "heavier and including". Usually when you say "heavier than", it excludes the one you're comparing it to. Small quibble, but a bit confusing nonetheless. --♫ Hurricanehink (talk) 15:27, 3 November 2012 (UTC)
Ah, I think I found where the confusion is. We have only produced einsteinium in labs, but it has been produced in at least one lab in macroscopic quantities, whereas all of the other transcalifornium elements have only been produced in microscopic quantities. StringTheory11 (t • c) 16:25, 3 November 2012 (UTC)
Oooh! Yea, that fixed my confusion, sorry about that. --♫ Hurricanehink (talk) 17:49, 3 November 2012 (UTC)
Do you think it's worth mentioning the potential g-block? Or because nothing post-118 has been discovered, it's not worth it?
This is already mentioned in the section "Futher periodic table extensions", so Already done. StringTheory11 (t • c) 04:14, 3 November 2012 (UTC)
"Other conventions and variations" - is largely unsourced.
The end of those two paragraphs are still unsourced though. --♫ Hurricanehink (talk) 15:27, 3 November 2012 (UTC)
After you get this, I'll be happy to support. --♫ Hurricanehink (talk) 17:49, 3 November 2012 (UTC)
Done, thank you Sandbh (talk) 02:50, 6 November 2012 (UTC)
Why does the image next to "First systemization attempts" exclude those up to 118?
Those elements were discovered after 2000, which doesn't have a color key on the chart. I'm not much of an image guru, so does someone want to go about updating the image with the new elements? StringTheory11 (t • c) 04:17, 3 November 2012 (UTC)
Do you want all the elements up to 118 to be included, or just the IUPAC-approved ones? Double sharp (talk) 08:11, 3 November 2012 (UTC)
Probably IUPAC-approved would work, if you can update that image. --♫ Hurricanehink (talk) 15:27, 3 November 2012 (UTC)
Done Added all the elements up to 118. Double sharp (talk) 03:06, 4 November 2012 (UTC)
Support A very comprehensive article that is also easy to read. Double sharp (talk) 03:27, 4 November 2012 (UTC)
Support Commentsreading through now - I'll make straightforward fixes as I go (please revert if I inadvertently change the meaning!) and jot queries below: Casliber (talk·contribs) 08:24, 6 November 2012 (UTC)
''Glenn Seaborg, an American scientist, made the 'revolutionary' suggestion - why is 'revolutionary' in quotes?
Removed the unencyclopedic word, so Done. StringTheory11 (t • c) 16:53, 6 November 2012 (UTC)
The number of physically possible elements is not known- I'd say "physically" is redundant (?)